Wishful thinking is rewarded

We make judgements quiterationally or “by the gut”. Not only experience and relevantinformation play...

October 12, 2018

We make judgements quiterationally or “by the gut”. Not only experience and relevantinformation play an important role, but also our preferences. A study by theMax PlanckInstitute for Metabolism Research in Cologne shows how the rewardsystem in the brainconveys judgements affected by one's own desires.

“In complex, confusing situations, we run the risk of making abiased judgement as soon as weprefer one conclusion over another,”explains Dr. Bojana Kuzmanovic, a scientist at the Max PlanckInstitute forMetabolism Research in Cologne. In her work, she investigated how people'sjudgment is influenced by their wishful thinking.

In the study, volunteers were asked to estimate the average and personalrisk of different negativeevents. They then learned the actual average riskand were able to adjust their own risk estimatesaccordingly. If the actualaverage risks were desirable (i.e. lower than initially estimated by therespondents), they were considered more than undesirable statistics.

Using an example, Kuzmanovic explains the phenomenon as follows: “By ignoring unpleasantinformation, we avoid drawing threateningconclusions. For example, we could neglect federalstatistics, which indicate ahigher risk of heart attack, because we think we have a particularlyhealthylifestyle.”

While the study participants carried out the survey, the scientistsrecorded their brain activityusing magnetic resonance tomography. They foundthat preferred judgements activate brainregions that otherwise reactparticularly strongly to rewards such as food or money. In addition,thescientists were able to show for the first time that the reward system in turninfluenced otherbrain regions that are involved in conclusion processes. Thestronger this neuronal influence was,the stronger the judgements of the studyparticipants were determined by their wishes.

So, our desires and preferences influence our judgment without usconsciously realizing it. Thesame brain systems that reinforce our efforts tomaximize rewards such as food and money wouldalso reinforce specificstrategies for constructing judgements. Dr. Marc Tittgemeyer, who led thestudy, adds: “The influence of preferences is independent of expertise. Wecan benefit from thispleasant self-strengthening effect as long as ourjudgements do not have serious consequences.However, when making importantdecisions, we should be aware of our tendency to distortjudgement and applystrategies to increase objectivity.”

Next, the researchers will investigate whether these and otherreward-dependent behaviours aredifferent in patients with metabolic diseasesthan in healthy individuals. Reward dependent braincircuits are closely linkedto homeostatic circuits that regulate energy demand and metabolismbased onsaturation and hunger signals. Thus, if homeostatic networks are altered bydisease, thiscould also affect reward-dependent brain areas and lead to moreimpulsive behaviour, forexample.